The sport of rowing is increasingly popular. In this port, a rowing crew propels a rowing shell through the water and races against a competing team or in a timed trial. Single-crewed shells are sometimes raced, but more commonly a racing shell is crewed by multiple rowers, sometimes with a coxswain. In such cases, an important aspect of the sport is for the rowers to synchronize their rowing strokes to the extent possible. Crew teams practice rowing on indoor rower devices, known colloquially as “ergometers” or “ergs.”
The ideal crew stroke consists of four phases, the catch, the drive, the extract, and the recovery, with the ratio of drive to recovery time being 1:2 (drive:recovery). Conventionally, the stern-most rower, known as the “stroke” rower, sets the pace for the successive rowers, assisted by commands from the coxswain. All of the rowers are seated on seats that slide on a short track and that move relative to the hull of the shell. During the drive phase of the stroke, the seats move relatively forward (i.e., towards the bow of the boat), while during the recovery phase of the stroke, the seats move relatively sternwards. In some cases, a forward rower will “rush” the stroke and reduce the recovery time relative to the drive time, in a manner out of synchronization with the stroke rower. When this happens, the seats of rowers to the stern, particularly the stroke rower, will be urged forward as the rower is sliding the seat sternward, thereby requiring an adjustment to those rower's strokes.